my brother, his family and i will be in st moritz(2 nights/1 day) and zermatt(3 nights/2 days) in Feb. we do not ski and my brother has a pacemaker(crtd). we are taking the glacier express from st moritz to zermatt. besides enjoying the snow, can you suggest what we can do? his son is 18 years old.

There are several peaks/viewing points you can visit near both towns, like Gornergrat, Klein Matterhorn, Corvatsch. Do make sure that your brother is allowed to go up to those altitudes. From St. Moritz, you can do a train trip to Tirano via the Bernina line. Suggestions and details are here and here. Sledging from Preda to Bergün is also worth looking into, see here.